Worldwide,
When I play my music at a reasonably loud level, everything in the room resonates. To keep this vibration from reaching my components and introducing noise I suspended the components. The place it makes the biggest difference is the turntable. But all components benefit from the isolation.
Regarding the speakers, I prevent my floor from resonating therefore the music is emanating from the speaker only and not from the floor as well.
Believe it or not it all made a huge difference. I highly recommend it, too bad I can't patent it but I didn't come up with it first.